\shapeTieColumn does not work after line break

[Peter Crighton]

I am reviving this old message because I stumbled over the problem, too.

Does anyone know how to make \shapeTieColumn (from openLilyLib) work in the top staff of a system after a line break?

2014-10-17 16:23 GMT+02:00 Neil Thornock <address@hidden>:

See the exchange below between myself and David. Hoping for an elegant solution to this problem.

---------- Forwarded message ----------
From: David Nalesnik <address@hidden>
Date: Thu, Oct 16, 2014 at 11:18 AM
Subject: Re: shapeTieColumn
To: Neil Thornock <address@hidden>

Hi Neil,

On Thu, Oct 16, 2014 at 11:05 AM, Neil Thornock <address@hidden> wrote:

Hi David,

Not sure this is worth an email to the Lily list...

I'm using your shapeTieColumn function. After a line break, the function works only if it is not the top staff of a system. So this breaks:

{ s1 \break <c' d' e'>8.~ \shapeTieColumn #'((()) (()) (((0 . -4) (0 . 1)     (0 . 0) (0 . 0))) (()) (())) <c' d' e'> }

Any ideas?

I've been poking around with this, and I really have no idea.  It _should_ work.

I added two print lines to the function to check if the offsets are happening.  They are. Run the following on your snippet:

%%%%%%%% function for offsetting control-points of a TieColumn %%%%%%%%%%%%%%%%%

shapeTieColumn =

#(define-music-function (parser location all-offsets) (list?)

   #{

     \once \override TieColumn #'after-line-breaking =

     #(lambda (grob)

        (let ((ties (ly:grob-array->list (ly:grob-object grob 'ties)))) ;(display ties) (newline)

          

          (for-each

           (lambda (tie offsets-for-broken-pair)

             (let* ((orig (ly:grob-original tie))

                    (siblings (ly:spanner-broken-into orig)))

               

               (format #t "before: ~a~%" (ly:grob-property orig 'control-points))

               

               (for-each

                (lambda (piece offsets-for-piece)

                  (if (pair? offsets-for-piece)

              

                      

                      (set! (ly:grob-property piece 'control-points)

                            (map

                             (lambda (x y) (coord-translate x y))

                             (ly:tie::calc-control-points piece)

                             offsets-for-piece))))

                (if (null? siblings)

                    (list orig)

                    siblings)

                offsets-for-broken-pair)

               

               (format #t "after: ~a~%" (ly:grob-property orig 'control-points))

               

               ))

           

           ties all-offsets)))

   #})

%%%%%%%%%%%%%

The problem also happens when the \break isn't manual.  Try:

{ 

  \repeat unfold 8 { R1 }  

  <c' d' e'>8.~

  \shapeTieColumn #'( (()) (()) ( ((0 . 4) (0 . 1)  (0 . 0) (0 . 0))))

  <c' d' e'> r8 r2 \repeat unfold 8 { R1 }

}

%%%%%%%%%%%%%%%%

My only guess is that the tweaking is happening at the wrong time--too late? Even though 'control-points is showing a change, the item has already been finished?

 

Honestly, I'm at a loss here.  You might want to forward this to the lists to see if someone else has an idea.

Best,

David

--
Peter Crighton | Musician & Music Engraver based in Mainz, Germany
http://www.petercrighton.de